Maguro or tuna was considered as trash fish, not preferred during the Edo period and its fatty part was discarded. A maturing period of 4-10 days is set in order to bring out best in maguro such as a fine sourness and faint sweetness of fat. Its sleek, shiny looking deserves the title of “king of sushi”. And there are actually 3 main grades of maguro or tuna that are commonly served including Akami being the darkest red, slightly lighter one is Chu toro and the lightest of the three, Otoro.
Marbled tuna(shimofuri) is the part in which it looks like the fat has fallen like a frost and melts like snow on your tongue then leaving only the umami taste.
The lined fatty tuna (Jabara) is the part that has white fat lines running through it. When you first take a bite, surge of aroma and umami flavor fills your mouth. After that, the potent fatty umami fills your mouth. The way the fat melts in your mouth differs between Jabara and marbling, so which you like better depends on preference.
Meji Maguro (AKA: Meji) caught in fixed net fishing is one type of sushi topping that you really should try. Meji is the larval fish of Pacific bluefin tuna, made and served at expensive restaurants, but not usually available as Edo-style sushi. Its fat is lighter and it doesn’t have the impact that fatty tuna has. Efforts are put into seasoning to avoid this. Using a pinch of ginger, Japanese basil or onion between the topping and rice, along with the wasabi, really brings out the fresh flavor of the young fish as well as the sweetness of this fatty part.
A purchase of raw tuna costs at least JPY 30,000 per kilogram. Furthermore, good tuna is judged not only by taste, but appearance is also highly regarded.
The surface is gradually oxidized by letting it sleep (mature) and the sushi chef makes sure that parts are cut of as they change color, when the timing is perfect for both the taste and appearance. In other words, skin is taken from the freshly purchased tuna, the meat of the fish darkened by blood (the blackened area that can’t be used as sushi toppings) is removed, the parts that have changed color are shaved off and then only the remaining, best parts used as toppings are left.
During the Edo period, tuna was not highly valued as a sushi topping and it was referred to as “Gezakana” meaning that it was inferior to normal fish. The reason was the big size of the tuna. At this time there was no ice, so tuna had to be salted. It was cut into blocks, salt was spread all over and in it, and that was it. At Uogashi (the market prior to Tsukiji) it was treated at shops that specialized in salting fish. The dark, discolored, salty chunks of flesh really were nothing but “Gezakana*”.
*Gezakana －Relatively low-cost sushi ingredients, such as gizzard shad and horse mackerel. Bluefin tuna used to be also called gezakana in the Edo period, for losing its freshness easily.
A single bite of the same bluefin tuna differs greatly depending on the part of the fish it came from.
The body of the fish is broadly categorized into the dorsal (back) and the ventral (belly) sides, which taste completely different. Of course the meat near the head tastes completely different from the meat near the tail. If you dig even deeper, there are parts that aren’t as well-known as the Otoro (fatty), Chutoro (medium fatty) and Akami (lean) tuna meats. We’d like to explain those now.
“Hachinomi (ハチの身) or Tsunotoro Nouten” is the meat from the crown of the head. It is fatty and rich and also called “Head Toro”. Only about 1kg of this precious meat can be taken from even a very large fish, and it is only shared with regular, loyal customers.
“Kamatoro (カマトロ)” is taken from behind the jaw. It is known as “shimofuri (霜降り)” or marbled meat. There are no veins in this part so the meat is soft and the marbling is more detailed than Otoro, so it is sticky and melts in your mouth. The balance of fat and sweetness in this part is unparalleled. It can be said that otoro (such as shimofuri and jabara) of tuna is the representative part of toro tuna. This is an image of the shimofuri on the right, and the jabara (蛇腹) on the left.
“Chiai (血合い)” is the part with the most veins, so it is a dark red color. It has a strong odor of blood and has multiple times the acidity of the lean meat, so it is not used as a sushi topping.
“Chiai Gishi (血合いぎし)” －Located right next to chiai, this is the meat you can taste the umami of the rich red meat and the sweetness of toro fat at the same time.
“Wakaremi (分かれ身)” is a precious part with very little meat found next to the dorsal fin. The part especially close to the dorsal fin is popular and called “Setoro (背トロ)”. Setoro has both the umami of akami and the umami of fat. The fat isn’t overbearing so you can eat a ton. However, this part is hard to get, even in high-quality tuna and is not available except to regular customers in almost all sushi restaurants.
A sushi chef, Hiroyuki Sato, serves a tossaki hand roll as the first sushi piece of the course. “Tossaki (突先)” is an exclusive cut of tuna that goes well with sushi rice using red vinegar, which is less sour but has more umami and flavor compared with white vinegar. Because tossaki is the base of the tuna’s head and it moves a lot, there are a lot of muscular striations. Therefore it needs to be prepared using the back of a knife carefully as if peeling it off (Hagashi). It is said that tossaki is a high-tuna-flavor cut. A couple of Sato’s apprentices also offer a hand roll to open up the meal in the same way.
The meat of tuna gets leaner and muscular striations are fewer towards the inner center of the body. “Tenpa (天端)”, surrounding the spine, is deeper in color and tastes stronger. It features the tender texture coming from the finest meat quality. This is also called Tenmi (天身).
“Hohoniku (ホホ肉)” or cheek meat is taken from below the eye, seasoned, grilled and made into gun-kan rolls. The taste is enhanced in this part by grilling.
“Hireshita (ヒレ下)”－Located right above the first pectoral fin. Characterized with the tender meat which is relatively low in fat content but rich with umami flavor. This truly is the valuable part of whether there will be even enough for 10 pieces of sushi from an over 200 kg tuna.
If you are fortunate enough to get an opportunity to taste these, you can take it as proof that you have been accepted as a regular and loyal customer. It is difficult to distinguish these parts by appearance alone, so make sure you try them at a sushi restaurant you can trust. Just for your reference.
There are mainly five methods for tuna fishing. “Ipponzuri” (catching fish with fishing poles) in Oma, Aomori prefecture, you see a lot through the media, is well known. However, the fact is that Long line fishing method and Purse seine fishing method are the ones catching the most tuna. The rest is Fixed net fishing method and Hikiami (Seine fishing method).
<Long line fishing method>
Long line fishing method
To hang a long line (Mikinawa) in the sea, covered with about 3000 fishhooks attached to branch lines (Edanawa), aiming at a path of schooling tuna.
<Purse seine fishing method>
A large-scale method of fishing by encircling a school of tuna with a net. Although it is efficient, there is a demerit of lowering the quality of fish because they struggle while getting caught. In addition, other kinds of fish and immature fish can be caught without distinction and that leads to overfishing.
<Fixed net fishing method>
Tuna have a habit of migrating to the same ocean area at the same time each year. A coastal fishing method called Fixed net fishing consists of placing a net in the sea and wait for a school of tuna. The advantage of this method is to be able to capture the fish alive without causing any injury or damage.
<Ipponzuri (catching fish with fishing poles)>
Ipponzuri (catching fish with fishing poles)
This method has the longest history and uses a pole of 4 – 6 meters to fish from a boat. Using a machine that winds up lines automatically and also using human hands, pull up tuna that weighs more than 100kg and lastly catch it by piercing gills with a harpoon.
<Hikiami (Seine fishing method)>
To catch fish by towing a bag-shaped net from a boat.
Fish farming is to hatch fish from eggs or to raise from juvenile fish right after hatching. Imported fish farming tuna, which is out in the market now, is actually fish fattening tuna that is raised bigger by feeding to full-grown fish. Fish fattening is to catch tuna by fixed net fishing method when they are skinny after egg-laying, and to fatten by feeding wild fish such as sardine and mackerel for three months.
We went to Tsujiki wholesale fish market today also, and actually got to enter at the time all food professionals are buying and selling.
The tuna auction begins at 5:00 am. Then about 6:30 am, intermediate wholesalers start lining up their winning bid tuna. Therefore, it is around the time when people like masters from sushi restaurants come to buy fish. Once professional deals settle down at 10:00 am, all the other visitors and foreign tourists are allowed to get in the market.
What exactly is the difference between on what is going on before and after 10:00 am? That is how determined sellers and buyers are. It is entirely full of sprit because it is a place for exchanging valuable information.
This is one situation I saw how they interact. As they talk about how Tuna, air transported from Boston, is fatty but doesn’t have any flavor of Tuna compared to the inshore ones, they let me try a piece. The one from inshore definitely tastes more as Tuna for sure.
“I’ll take about a 20cm width of the belly, around this part of the inshore one.”
Zuke is one of the traditional Edo-style sushi methods. It is said that it was started in the Edo period to stop tuna from rotting when there were large amounts of the fish in the market. Now that there has been advances in refrigeration technology, it’s no longer necessary, but maturing the fish gives it a completely different taste and brings out its umami. Zuke is divided into two broad methods. Here we describe the characteristics of each.
Recently, most sushi restaurants incorporate the “Single Zuke”.
Each slice of tuna is soaked separately, so it can mature quickly. The immersion time is only a few minutes. The idea is to marinate just enough so that the tuna’s aroma remains and the soy sauce doesn’t overtake it.
On the other hand, the old Edo-style method is to perform Zuke after parboiling.
Parboiling means to wrap the fish in a wet cloth, and poor boiling water on the wrapping until the color of the tuna changes color, then turn the fish over and repeat the process. The fish is then put in ice water so the heat doesn’t go too deep in the meat. It is immediately removed once it cools so that it doesn’t get too watery. The tuna is then put in Zuke soy sauce and left to marinate for about half a day. In this method, the soy sauce only soaks into the surface part where the color changed from the parboiling, so the flavor of the tuna remains.
Both methods keep the maximum tuna flavor possible. Tuna is an essential part of Edo-style sushi. There is great diversity between sushi restaurants in the parts, marinating time and flavor of Zuke, which creates a new, original flavor when the lean meat of the tuna soaks up the soy sauce. The fattiest cuts of tuna are most popular. The lean meat has only become more popular due to a rekindled interest in zuke, but in fact during the peak of the bubble economy, there was a time when high-end restaurants in Ginza didn’t know what to do with all their leftover lean tuna meat. It’s almost unbelievable to think of it now.
How the fish is butchered also changes the taste. If the fish suffers and struggles, the body wears and may be damaged, circulating oxidized blood throughout the body, which makes it lose flavor. For fish of high value such as sea bream, flounder, yellowtail, rudderfish and tuna, a method called “ikejime” is used.
The taste of tuna is said to be determined based on the preparations after being caught. The tuna is caught with as little suffering as possible and the nerves are killed immediately for an instant death. Generally, blood is then drained perfectly, entrails and gills are removed, the tail cut off and then the fish is placed in ice-water to lower the body temperature.
The medulla oblongata and main artery of the fish are cut and a kitchen knife is inserted into the base of the tail to drain the blood. A thin metal rod is inserted into the backbone to paralyze the nerves and at the same time controls the putrefied materials that come out of the spinal cord.
This extends the time until rigor mortis sets in, making it easier to maintain freshness and simultaneously preventing blood from circulating in the body, which also prevents the fishy smell.
Freezing the fish to death in ice water is called “nojime”. This method is generally used for small fish such as sardines, horse mackerel and mackerel that are fished in large volume. Although the freshness of the fish deteriorates more quickly than in the case of “ikejime,” it can be done in large quantities without a lot of labor and maintains a certain level of freshness afterwards.
At fish markets, the term “kill” is not used for living fish, instead the word “shimeru” meaning to close or tighten. The term “dead fish” is also not used. Instead the term “nojime” is used for fish that died naturally en route to the market. This stems from the awe of precious life and turning that life into food.
Marbled tuna (shimofuri) is the part in which it looks like the fat has fallen like a frost and melts like snow on your tongue then leaving only the umami taste.
The lined fatty tuna (Jabara) is the part that has white fat lines running through it. When you first take a bite, surge of aroma and umami flavor fills your mouth. After that, the potent fatty umami fills your mouth. The way the fat melts in your mouth differs between Jabara and marbling, so which you like better depends on preference.
During the Edo period, tuna was not highly valued as a sushi topping and it was referred to as “
A single bite of the same bluefin tuna differs greatly depending on the part of the fish it came from.
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A sushi chef, Hiroyuki Sato, serves a tossaki hand roll as the first sushi piece of the course. “
The meat of tuna gets leaner and muscular striations are fewer towards the inner center of the body. “
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“Hireshita (ヒレ下)”
Zuke is one of the traditional Edo-style sushi methods. It is said that it was started in the Edo period to stop tuna from rotting when there were large amounts of the fish in the market. Now that there has been advances in refrigeration technology, it’s no longer necessary, but maturing the fish gives it a completely different taste and brings out its umami. Zuke is divided into two broad methods. Here we describe the characteristics of each.
How the fish is butchered also changes the taste. If the fish suffers and struggles, the body wears and may be damaged, circulating oxidized blood throughout the body, which makes it lose flavor. For fish of high value such as sea bream, flounder, yellowtail, rudderfish and tuna, a method called “
Freezing the fish to death in ice water is called “